extreme01ta

iTrader: (2)

for ttt

bigdsz

iTrader: (1)

You know as important as this issue is, you would think that it would have generated a lot more interest, We need more input from guys like Jason.

extreme01ta

iTrader: (2)

ttt to the top

JF WS6

Are you sure the heads were unmilled when you bought them? Cause I could see if they were shaved .015 when you bought them, then you did another .030 more you could possibly have tight clearances like that..... but I have never heard of such a small cam being that tight with just .030 taken off. The cam has small lift, not much duration and on a 112 LSA, plus you have the smaller 2.02 intake valves.

Just for example, my last setup was a 232/240 .598/.605 112LSA 108ICL XER Comp cam and a set of Stage II LS6 heads shaved .015 with graphite gaskets and I still had .072 clearance. So how I had .072 clearance and you only have .056 seems a little lost on me. You were using head gaskets when you checked the clearance right?

extreme01ta

iTrader: (2)

Oh man! I'm suposed to use gaskets? lol Yes I had gaskets but thanks for asking. I CC'ed the chambers before I milled them and they were the stock size. I bought them used and he said that they were unmilled. I've pretty much decided to give'r hell and see what happens. I guess I will let you guys know what happens.
thanks for the input, Richard

JF WS6

In all honesty, I think you will be fine.

bigdsz

iTrader: (1)

Extreme , I've got AS heads and am in the process of installing a CC xer 228/230 and am going to have to flycut my pistons. I'm only running .043 with unmilled heads and 2.02 valves. I've got a post going in this section on measuring p/v clearance read it. What i have found is that when Jay set these heads up he hung the intakes way out on the edge of the valve seat to maximize flow and that's the reason his 5.3's are so tight. Also to find out how much your heads have been milled, simply measure the thickness of the head bolt boss closest to the exhaust port , unmilled heads measure 1.615". Also, from the deck of the head to where the valve cover gasket rests on the head is 4.750" on unmilled heads.

extreme01ta

iTrader: (2)

Thanks for the input on measuring the head to see if it has been milled, I will check that and get back to you on it. I read your post on measuring the clearance, a little confusing for me. And my heads are already installed on motor so it wouldn't work for me anyway. You say you have .043 and need to flycut. my whole reason for milling was to bump up compression. If I fly cut I will lose what I gained and just as well not have bothered

bigdsz

iTrader: (1)

The way I understand fly cutting, is that if the intake is cut about .050 and the exhaust .025 then you only lose a little over 1 cc, so there is minimal loss of compression.

extreme01ta

iTrader: (2)

I can't get an acurate measurement on the head thickness with it installed. If I end up pulling the head can I reuse the cometic gasket? and how would I go about flycutting the piston?

bigdsz

iTrader: (1)

I think you can reuse the Cometics but I'm not positive. I clayed my intake valve last anight and verified that I only have around .045 clearance, so I have no options I have to fly cut. My AS's are not milled.

mshiznitzh

Could you not use a thinker head gasket? Sorry I don't know much about this kind of stuff.

bigdsz

iTrader: (1)

I think there are .070 head gaskets around but what happens is your Quench gets screwed up. I really need to use .045 Cometics bu I refuse to pay $ 85 for each gasket.

extreme01ta

iTrader: (2)

Well I got good news and bad news. I got the engine completely installed and running here the other day with no clearance issues with my .046 intake valve clearance. at least at lower rpm, I have not drove the car yet just reved up a little bit in neutral. The bad news is that I fell victom to the, good 'ol notch in the head with the mls gasket, coolant leak. and am not very happy about it. I called cometic and asked them about it and they did not know any thing about it, they said they did not make two differant styles of head gasket for the ls1's so I should be "good to go" well they were wrong! so I get to drop the engine to r&r the heads to change the gaskets, but I guess it will be a good chance to inspect for p to v contact. Does any one know the compressed thickness of a stock gm graphite head gasket?

Beast96Z

iTrader: (21)

.054" is the GM graphite thickness. What model were the heads with the notch?

bigdsz

iTrader: (1)

Compressed thickness for the graphite gaskets is .053-.054, anyone that says differently is wrong. I measured them in about 20 different places. Sorry to hear about your problems. I'm up and running, due to a screw up using the Isky tool my intakes ended up being cut .060-.070 instead of .045-.050. You really want to get Cometics, I ended up having to use OEM graphites. No one had .045 Cometics so my quench is off.

extreme01ta

iTrader: (2)

I believe they are 853's. Yeh I thought I wanted cometics too but not after this. I will also measure the head thickness while they are off so I know for sure what I've got as far as how much they have been milled. Thanks for the input on the thickness of the stock gaskets.

bigdsz

iTrader: (1)

The notched heads were the '97,'98, early '99 LS1's weren't they?

extreme01ta

iTrader: (2)

Yeh I think these ones were off of a '99 or '00. has any one ever had a problem with the gm gaskets?

bigdsz

iTrader: (1)

I have used the graphite gaskets without any issues. You realize it is not necessary to drop the engine to remove the heads. Let us know what you find clearance wise.